Sustainable energy solutions for

South African local government

A practical guide

Produced by Sustainable Energy Africa

The Green Building

9B Bell Crescent Close

Westlake

7945

tel: 021- 7023622

fax: 021-7023625

email: info@sustainable.org.za

website: www.sustainable.org.za

© Sustainable Energy Africa, Cape Town 2017

August 2017

Report citation

SEA. 2017.

Sustainable energy solutions for South African local government: a practical guide

(Cape Town: Sustainable Energy Africa).

Design and layout: dotted line design www.dottedlinedesign.co.za

Wind Energy

Overview Wind energy is generated when the kinetic energy of the wind is harnessed by wind turbines and converted into mechanical energy. To generate electricity, this mechanical energy is used to rotate a generator situated in the hub of each turbine. Wind turbines can range in size from small home based 50W units to large 5MW commercial units. Offshore turbines are even bigger at 8MW. A 3MW wind turbine can generate enough electricity to supply around 900 South African middle-income households with a consumption of 800kWh per month. Currently, more than 1400MW of wind turbines are producing power with another 2300MW at various stages of planning and construction.

Wind turbines for commercial power generation are generally arranged in an array, collectively called a wind farm. Wind farms are typically located in areas with a consistently high level of wind. Their performance increases exponentially with the increase in wind speed. Wind speeds are stronger at higher elevations, which is why most wind turbines are mounted on around 100m high masts. The output of a wind turbine is determined by its power rating and the load factor.

The Darling Wind farm, South Africa’s first commercial wind farm that was financed through a 20-year power purchase agreement (PPA) with the City of Cape Town. It is noted that this type of municipal PPAs is no longer legally possible.

Recent research by the CSIR found that South Africa has excellent wind resources (see wind map below). If appropriate turbines for higher or lower wind speeds are selected 80% of the South African land mass has sufficient wind for turbines to achieve a load factor of more than 30% which makes them economically viable. Therefore wind turbines could be installed in many parts of the country taking advantage of different weather patterns of each area to produce more consistent output from this source of energy. Wind parks with a capacity of 50 GW would require only 0.4% of the South African land mass and could supply 150TWh/year. This is 2/3 of the current annual electricity consumption of the country1.

1 CSIR, Fraunhofer, Eskom & Sanedi (2016) Wind and Solar PV.

Figure 1: Wind turbines at Darling wind farm near Yzerfontein

Source: https://en.wikipedia.org/wiki/File:Darling_South_Africa_wind_turbines.jpg

Photographer: Kalle Pihlajasaari

Figure 2: Map of South Africa showing the average wind speed at 100m height

Source: CSIR, Fraunhofer, Eskom & Sanedi (2016) Wind and Solar PV Resource Aggregation Study p. 10

Municipal Initiatives

200

Large Wind Parks

Large wind turbines are currently the most financially feasible renewable energy technology available. Through the Renewable Energy Independent Power Producer Procurement (REIPPP) Programme several windfarms have been installed or approved. The cost of electricity generated by wind turbines as decreased from R1.42/kWh in the first bidding window of the programme to R0.62/kWh in the fourth. Wind parks approved in the first window started operating in early 2014. Approved project in the fourth window are still at planning stage. This cost per kWh is about 40% lower than the cost of electricity generated in the new Eskom coal fired power stations (Medupi and Kusile) and makes wind the cheapest new built technology for electricity generation in South Africa. Because wind generated electricity is not consistent, it needs to be paired with other generation options such as gas (which can quickly respond to decreases in supply from wind or other sources) in the national generation mix.

Large wind turbines and wind parks require Environmental Impact Assessments (EIA) to be conducted. Negative environmental impacts can be avoided through careful choice of location or can be mitigated through technical measures such switching off turbines at certain times of day or year. The Department of Environmental Affairs has published the Draft EIA Guidelines for Renewable Energy Project2 that need to be followed.

Small Wind Turbines

In many municipalities small wind turbines will be or have already been installed by residents. Small wind turbines are used for generating electricity for a house, mini-grid or to charge batteries. They can be installed on-grid (grid-tied) or off-grid. The implications of small wind turbines for the municipality are similar to those of PV systems described in the section on Solar PV Systems below.

Small turbines do not require an EIA but they require a municipal building permit because they are structures according to the National Building regulations, and protrude more than the permitted height above the ground or above existing buildings. The chapter on municipal mandates: planning, regulation and service delivery explains the role and responsibility of municipalities in approving applications for renewable energy installations. Two types of small turbines can be distinguished: turbines with horizontal and vertical axis.

Horizontal Axis turbines

These turbines are technically similar to large turbines. Turbines available in South Africa typically range from less than 1kW to 10kW.

Horizontal turbines are most effective when installed significantly above surrounding buildings and trees to avoid turbulent flow. They can be installed on towers of 10 to 20 m height or attached to buildings. Installations on towers are generally safer because turbines cause vibrations that may cause damage to buildings. Some taller installations may not be permitted in urban areas due to height restrictions.

2 DEA (2013) EIA Guidelines for Renewable Energy Projects.

Figure 3: Small horizontal axis turbine

Source: http://www.geograph.org.uk/photo/4079521

Large wind turbines are currently the most

financially feasible renewable energy

technology available.

Wind energy

201

Vertical Axis turbines

This type of turbines is not very common. Vertical axis turbines are less efficient than turbines with horizontal axis in converting wind into electricity, especially at high wind speed. On the upside, this turbine type better manages turbulences that occur in the vicinity of buildings and close to the ground. This is an advantage in urban areas with height restrictions or if a turbine is being installed between buildings and trees.

ImplementationCurrently, some rural municipalities have large, multi-MW wind parks installed in their areas, funded through the REIPPP programme. These municipalities enjoy significant economic development benefits such as job creation and contributions to socio-economic development. SALGA has published a brochure how municipalities can maximise these benefits3.

Financial Aspects

Large wind turbines generate electricity at the lowest cost compared to all other technologies. The cost of electricity generated by the latest wind parks will be around R0.62/kWh4.

Reliable data on the cost of electricity generated by small turbines is not available. The current price of a 2kW turbine alone is around R18 000 without the support pole, installation, inverter and other components. The cost of power also depends strongly on the micro location and maintenance (see case study below 1.3.2).

Barriers and opportunities

Large wind turbines are a mature and reliable technology but their installation requires comprehensive planning, careful site selection and environmental impact assessment. Municipalities cannot influence the location of large scale wind projects funded through the REIPPP. The main barrier for implementing projects over 10MW outside of the REIPPP is the very complex planning and approval process requiring a Ministerial Determination. The Minister of Energy must approve large project to be in line with the Integrated Resource Plan (IRP) that determines the mix of sources of electricity generation. At the time of writing no project outside of the REIPPP had received this approval, although some municipalities are moving in this direction. Municipalities should monitor policy developments in this regard (for details see the chapter on Power Purchase Agreements, page 374).

Municipalities can create an enabling environment for small turbines by facilitating the integration of small scale electricity generation in the municipal grid and by simplifying development application and approval of small turbines and other renewable energy options (see chapter on Municipal mandates: planning, regulation, service delivery, page 313 and the chapter on Solar PV systems, page 205). The Sherwood case study shows that small turbine installations are still quite complicated to install and operate, indicating that the technology is less mature than large turbines. An additional barrier is the uncertainty of the cost of generated electricity. These barriers will only be removed once the technology has matured.

3 SALGA (2013) Local Economic Benefits of the REIPPP.

4 2017 prices.

Figure 4: Small vertical axis turbine

Source: http://www.geograph.org.uk/photo/3116833

Photographer: Ashley Dace

These municipalities enjoy significant economic development benefits such as job creation and contributions to socio-economic development.

202

Municipal Initiatives

Case Study 1: Jeffreys Bay Wind Farm*

This project is one of the first and largest wind farms in South Africa funded through the REIPPP programme. The wind farm site spans 3 700 hectares on which 60 wind turbines have been erected. Construction started in December 2012 and started commercial operations by mid-2014.The wind farm supplies the Eskom 132kV grid line and generates 460 000 MWh per year. This is enough clean electrical energy to power more than 100 000 average South African households.

Each wind turbine stands 80m tall with blades 49m long and a rotor diameter of 101 metres. The average rotation of the blades is between 6 and 16 rotations per minute. Each turbine can generate 2.3 MW of electricity. The project supports socio-economic development initiatives to communities living within 50km radius of the wind farm:

� Enterprise development includes initiatives to assist and accelerate the sustainability of local enterprises and intends to support emerging black farmers in the area.

� The socio-economic focus is on health programmes (HIV and Aids, and vulnerable children programmes), youth upliftment – sports programmes and education support programmes, including:

� early childhood development, as part of a crèche support programme

� numeracy and literacy interventions at primary school level

� support for mathematics and science programmes at secondary school level

� a scholarship programme for engineering related studies at tertiary level.

Further benefits to the community include six percentage ownership of the Jeffreys Bay Wind Farm by a Community Trust. The project supports scholarship and internship programmes especially for young mechatronics and electricity engineering students in collaboration with several South African universities.

Figure 5: Turbines at Jeffreys Bay Wind Farm

Source: NJR ZA, https://commons.wikimedia.org/wiki/File:Jeffreys_Bay_Windfarm-001.JPG

* This case study draws extensively from the website: http://jeffreysbaywindfarm.co.za, accessed January 2017. Unless referenced otherwise, information is sourced from this site.

203

Case study: Wind energy

Case study 2: Small turbines in Sherwood and Westville, Durban

The owner of Breez air conditioners in Sherwood Durban intends to sell small wind turbines in the future5. In 2016 he set up a prototype 1kW turbine on a 10m high pole in order to test and gather experience about the product. The wind turbine is combined with a 2kW PV panel. The technologies jointly feed a battery bank and inverters that supply electricity for lighting and office machines of the business. The batteries allow the business to continue working during longer electricity supply interruptions (load shedding) provided that large loads are switched off.

The cost of the turbine is around R18 000. In addition the pole costs R20 000. The photographs show the wind turbine and PV panels in the company’s car park and the inverters, batteries and switchboard in a corner of the storeroom.

5 Information provided in personal communication with M. Overall, 1/2017.

Figure 7: Inverters, batteries and switchboard

Photographer: S Godehart

Figure 8: PV panels next to the wind turbine support pole

Photographer: S Godehart

Figure 6: Wind turbine in Sherwood, DurbanPhotographer: S G

odehart

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Municipal Initiatives

At a private residence in Westville a 2kW wind turbine has been installed that feeds a battery bank and an inverter. The wind turbine was installed in 2008, at a height of 11m above ground on a pole fixed to the garage roof 6. The tubular pole was secured with cables to limit movements 7. The pole is installed on a hinge so that the turbine can be lowered for maintenance. At the same time a Solar Water Heater was installed.

The owner has recorded the electricity purchased from the grid before and after the installation of the turbine and solar water heater. The graph shows a reduction of around 500kWh/month in electricity purchased after the installations. After resolving technical problems with the inverter consistent monthly savings of around 400kWh/ months were achieved. However it was not metered much the wind turbine and the solar water heater contributed to the savings.

The owners of the turbines stated the following observations: � Both installers are happy with the electricity generation but state that

the efficiency of the turbine depends on the exposure to wind at the micro location. Both turbines are installed close to trees impacting on their efficiency. Better locations would be along the coast or at cliffs.

� Both are concerned about maintenance. The turbines require maintenance as the bearings of moving parts wear out. Access to the turbines for maintenance is complicated. A free standing turbine can only be accessed with a ‘cherry picker’. Especially free standing poles move in the wind resulting in stress on the bearings.

� Worn bearings result in increased noise of the turbines.

Support OrganisationSAWEA South African Wind Energy Associationwww.sawea.org.za

6 Information provided in personal communication with H. Osborn 1/2017.

7 The PV panels on the roof have only been installed in 2012.

Figure 9: 2kW turbine in Westville, Durban

Photographer: S Godehart

Figure 10: Fixture of cable securing pole

Photographer: S Godehart

Figure 11: Monitoring of Monthly Energy Consumption House Osborn

Source: H. Osborn

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House Osborn: Monthly Electricity Consumption

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